On 28/08/2011 13:02, Adam Lea wrote:
On 28/08/11 01:17, Tudor Hughes wrote:
On Aug 27, 11:53 pm, "Dave Liquorice"
wrote:
On Sat, 27 Aug 2011 23:04:51 +0100, Fonzy wrote:
winds up to 80mph, wow

Sustained or gust?

The other side of the pond and in relation to hurricanes the quoted
speeds refer to sustained wind speeds.

This side of the pond most weather reports that headline wind speeds
generally are refering to a single peak gust at an exposed place for
the entire storm.

Such gusts are anything from 10 to 20mph above the sustained wind
speed.

The British media give a very false impression to the general public
of what a sustained winds speed of 60mph is actually like. It'll have
you off your feet given half a chance and would wreak devastation
through an normal urban enviroment.

--
Cheers Dave.
Nr Garrigill, Cumbria. 421m ASL.

It probably would but I have yet to see, after a thorough
trawl of METARs in North Carolina and Virginia just now and a few
hours ago, a sustained wind speed of more than 52 mph, which is Force
9. The rainfall is tremendous and a hazard in itself but the wind
speeds would be familiar to anyone in the Hebrides. Worse things
happens elsewhere which we don't hear about, so why all the fuss?

Tudor Hughes, Warlingham, Surrey.

Of the four destructive forces of a hurricane, winds rank third.

The majority of the deaths in a hurricane historically are from drowning.

It is the storm surge (dependant on the width as well as intensity,
and Irene is a huge hurricane) and the 8-12 inches of rain coinciding
with a spring tide, coupled with the fact that NY is surrounded by
water that is the major cause for concern. How many Hebridean storms
produce a foot of rain and raise the sea level by 8 ft?

From the NHC public advisory:

"BATTERY PARK NEW YORK CITY HAS RECENTLY REPORTED A TOTAL WATER LEVEL
NEAR 8.6 FEET"


AIUI, the "Battery Park" guage measurements are above mean LOW water so
they are nearly always positive.

New York does not have a great tidal range and the sea defences are
about 5 feet above maximum HIGH water level, so to work out the level of
flooding in NYC you would need tidal range information as well.

Whilst there was some flooding in the city, the feared inundation of
some of the subway tunnels (which would have happened if the sea level
had gone more than a foot or so over the defences at Battery) did not
happen - as the Mayor said they "dodged the bullet". The most serious
flooding seems to have been in the suburbs and upstate due to excessive
rainfall on saturated ground overwhelming the drainage network.

While it seems the main damage caused by Irene will be flood related,
many of the casualties have been wind-related, often involving uprooted
trees.

--
- Yokel -

Yokel posts via a spam-trap account which is not read.